have some kind of a secure key so that i can reinstall this application should my disk crashes or i get a new machine.

I evaluate a lot of s/w and do a lot of activity on my machine. due to this i do need to reinstall Windows sometimes. it would be nice to have the working copy of this s/w again so that i can reuse all its features. if i have some key that i can manually type or if the activation s/w can somehow remember tht i have used it before it would be a nice plus.
Also there should be some feature to encrypt all the files so that it can be used even if multiple pple are using it.